What type of vapors are known to attack the mucous membranes?

Irritant vapors are specifically associated with the ability to attack mucous membranes in the respiratory system, as well as in the eyes and other soft tissue areas. These vapors often cause immediate and noticeable effects such as tearing, coughing, and inflammation, which are direct responses of the body to the irritating properties of the substances present in the vapors. This reaction occurs due to the chemical nature of irritant vapors, which can disrupt the normal functioning of cellular tissues and elicit a defensive response from the body.

While odorous vapors may also affect sensory perception and create discomfort, they do not necessarily have the same direct damaging effects on mucous membranes as irritant vapors. Volatile vapors refer more broadly to substances that can easily vaporize, and while they can also be irritants, not all volatile vapors affect mucous membranes in the same way. Toxic vapors, on the other hand, imply a broader range of harmful effects, which may include systemic toxicity affecting various organs, but the term does not specifically denote the particular action of attacking mucous membranes. Thus, irritant vapors are uniquely recognized for their immediate, localized effects on mucous membranes, making them the correct answer in this context.